The present invention relates to video surveillance cameras and, more particularly, to an assembly for adjusting the back focus of a video surveillance camera.
Video surveillance cameras must be able to provide clear and distinct images since such images may be used for security, evidentiary, identification, or other similar purposes. Present camera systems generally provide for adjustment of the back focus by moving the image sensor forward or backward while the lens stays stationary. Alternatively, for camera systems where the image sensor remains stationary, back focus is accomplished by physically adjusting the linear location of the lens assembly by screwing the lens assembly in and out of the camera body's threaded bushing. The first method is not efficient or practical for thermal management of the image sensor. The second method requires the use of tools to secure the position of the lens, which generally is not a user-friendly solution.
It is therefore desirable to provide a video surveillance camera in which the back focus can be easily adjusted and securely set. Moreover, the back focus assembly of the surveillance camera should have a minimum number of movable parts and be easy and inexpensive to manufacture, use, and maintain.